Chemical grouting proportioning pumping method and apparatus

ABSTRACT

Grouting reactants are mixed from separate supplies before delivery by driving a hydraulic pump and creating a constant flow of hydraulic fluid, dividing the hydraulic flow into two rotary hydraulic motors, controlling the hydraulic exhaust of those motors individually to establish a rotation ratio of the motors, and mechanically coupling each of the motors to a rotary pump for pumping a grouting reactant. Thereby the ratio of grouting reactants is precisely controlled. The speed of the hydraulic motors are controlled according to flow meters adjacent the reactant pumps so that the desired flow ratio of reactants is established. An overpressure switch in one of the reactant pump discharge lines cuts off hydraulic fluid to both hydraulic motors so that the single operator may shut down the reactant pumps simply by shutting off a valve in a discharge line far removed from the pumps.

United States Patent Herbert Leland Parsons [72] Inventor P.0. Box 46,Georges Rd., Franklin Park,

[54] CHEMICAL GROUTING PROPORTIONING PUMPING METHOD AND APPARATUS 7Claims, 2 Drawing Figs.

Constant flow filter Rellrvair 2,592,940 4/1952 Monoyer 103/51 3,192,7187/1965 Bieri 103/49 X 3,223,040 12/1965 Dinkelkamp 103/49 X 3,323,4626/1967 Turzillo et al 103/49 F ORElGN PATENTS 124,793 4/1919 GreatBritain 60/53 Primary Examiner-David J. Williamowsky AssistantExaminer-Philip C. Kannan AttorneyLittlepage, Quaintance, Wray &Aisenberg ABSTRACT: Grouting reactants are mixed from separate suppliesbefore delivery by driving a hydraulic pump and creating a constant flowof hydraulic fluid, dividing the hydraulic flow into two rotaryhydraulic motors, controlling the hydraulic exhaust of those motorsindividually to establish a rotation ratio of the motors, andmechanically coupling each of the motors to a rotary pump for pumping agrouting reactant. Thereby the ratio of grouting reactants is preciselycontrolled. The speed of the hydraulic motors are controlled accordingto flow meters adjacent the reactant pumps so that the desired flowratio of reactants is established. An overpressure switch in one of thereactant pump discharge lines cuts off hydraulic fluid to both hydraulicmotors-so that the single operator may shut down the reactant pumpssimply by shutting off a valve in a discharge line far removed from thepumps.

Mixing chamber Injection nozzol PATENIEUSEPMIBII v 3.604.213 SHEEI 1 UF2 ESTABLISH HYDRAULIC PRESSURE CONTROL FLOW THROUGH PARALLEL HYDRAULICMOTORS DRIVE INDIVIDUAL PUMPS AT DESIRED SPEED RATIO DRAW FLUIDS FROMSEPARATE TANKS 7 MIX AND PROPORTION FLUIDS INVENTOR HERBERT L. PARSONS aduh/MU 5% ii k7 PATENTEU SEP 1 4 I971 SHEET 2 0F 2 A 0N .Tk anEozu T 22W not zoioaom mm r mm acon. uooawA h v m v IIIV S E A 2:55: 529m vINVENTOR HERBERT L. PARSONS QWa7 22 A 4 Y ATTORNEYS CHEMICAL GROUTINGPROPORTIONING PUMPING METHOD AND APPARATUS This is acontinuation-in-part of copending U.S. Pat. application Ser. No.651,6l2, filed July 6, 1967, by Herbert L. Parsons for ProportioningPumping Method and Apparatus." That application has been abandoned.

BACKGROUND OF THE INVENTION This invention relates to improved equipmentfor precisely proportioning and mixing two or more grouting chemicalsunder varying field conditions, at variable pressures and volumes beforeinjecting the materials in the ground for soil stabilization and forwater control purposes.

The object of injecting controlled chemical grouting solutions into soilis to modify physical properties of given soil to meet engineering andconstruction requirements.

Soil is the foundation upon which we base our shelter, ourtransportation, our recreation, and our water conservation in all partsof the world. As is well known, soil in its natural state frequentlypresents engineering design and construction problems. Soil problems arebecoming more evident and critical as our population increases. As therate of building increases, less desirable building sites are selectedby necessity. Demands for underground construction are continuouslygenerated by rapidly developing space technology requirements, masstransportation requirements, and others.

Various methods and techniques are used to alter soil properties and tomeet numerous soil problems. Many needed soil modifications forengineering and construction purposes such as water control, increasedbearing ability, and elimination of quicksand type of conditions, etc.can be obtained their injecting one or more of the recently developedchemical grouting materials under pressure into inferior soils.

At this stage of the art of chemical'grouting, one of the major problemsin the performance of application work is the lack of satisfactorychemical proportioning equipment for field use. Pumping equipment usedat this time mainly lacks precision and versatility necessary forproportioning two or more chemicals while meeting the variableconditions in field grouting.

One of the difficulties with pumping equipment in use at this time isthe lack of infinitely and rapidly adjustable equipment. The presentinvention provides hydraulic pump drives which are rapidly adjustableover infinite settings to provide infinitely varying ratios of mixedfluids.

Essentially four basic systems and types of equipment have been used toapply chemical grouting solutions. These are usually designated asproportioning system two solution systems, batch systems and the twoshot system.

In the two shot system (Joosten process), a single mixing and pumpingsystem is used. First, the base grouting material, silicate, is injectedin the soil. Second the equipment, mixing tank, pump, and hoses arewashed out with water, and, third, the reactant, sodium chloride, ismixed and injected into the soil. The system has its drawbacks becausethe thorough and adequate mixing of the two materials in the soil isquestionable, and sometimes the two components do not make contact.

The batch systems are methods in which the base grouting materials andthe catalyst are mixed in one tank, and the batch is then pumped intothe ground, using almost any type of pump. This system has three majorlimitations: 1) The entire batch must be used within the establishedinduction period. That is not always possible, since pumping rates oftendecrease as pumping continues; thus, the danger of gelation in theequipment is always present. 2) It is difficult to vary an inductionperiod during pumping of a batch. For some applications, economy andvarying water conditions necessitate changing the induction period. 3)The most severe limitation is that, because of its nature, it is notpossible to use a batch system with very short induction periods. Veryshort gel times are essential at some point during most applications.

Two solution systems permit working conveniently with only onepredetermined gel time. This fixed gel time is usually adequate only inthe simplest applications. In addition, if gel times are changed, itrequires personnel and laboratory equipment ordinarily uncommon orinadaptable to a construction site. In that method, equal volumes ofsolutions are mixed in two tanks and blended into the third tank inequal proportions. From the third tank the final solution is pumped intothe soil.

Proportioning systems are the most flexible and the best to use ingrouting work, since varying volume rates and pressures are desired inall but the most simple grouting applications. At the present time,electrical and gasoline engine powered and airpower-driven variableproportioning systems have been constructed and used. However, whenthese units have been designed to give all the variablecharacteristicsrequired, they have resulted in equipment which is bulky,heavy, and requires highly skilled operating personnel of a type notcommon to field and construction operations. The many proportioningsystems which are known for mixing reactants in varied applications havesimilar drawbacks.

Chemical soil treatment systems showing the most advantages forinjection grouting methods have common requirements that two or moresolutions (base solution plus catalyst and/or retardants and/oradditives must be accurately proportioned while being injected into thesoil. Application usually occurs under adverse construction conditionswith the added difficulty of variable pressure and volume requirements.

An object of this invention is to provide improvements in chemicalgrouting methods and apparatus which have accuracy and versatility inhandling a variety of materials, and which have simplicity of operationheretofore unknown in the art of chemical soil grouting.

The present proportioning pumping system has a hydraulic pressuresupply, hydraulic axial piston motors and temperature-compensatedflowvalves to control the speed ratio of the motors. Each motor drives avariable volume and pressure pump, which delivers chemicals or additivesfrom the mixing tanks and in turn pumps the material through the systemof transfer lines, control valves, mixing chamber into the injectionpipe and to the point of application in the soil.

One objective of the present invention is the provision of improvedgrouting (W/H./W) and methods employing simple steps and controls toaccurately proportion and pump grouting materials into soil.

This invention has as another objective the provision of light weightapparatus for the readily variable proportioning, mixing and injectingof grouting chemicals and catalyst.

Another objective of this invention is the provision of variableproportioning pumping methods and apparatus for mixing reagents.

Further objectives of this invention will be apparent from thespecification and from exemplary embodiments of the invention as shownin the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow regeneration of stepsin performing the method of proportioning fluids.

FIG. 2 is a general schematic representation of the interrelation ofelements of this invention.

DETAILED DESCRIPTION OF THE DRAWINGS Referring to the drawings, FIG. 1is a flow chart of steps in the method of pumping and proportioningmaterials for grouting. First, a uniform source of hydraulic pressure isestablished. Then the hydraulic pressure is applied to at least tworotary motors whose speeds are controlled by exhaust valves. The rotary,motors in turn drive individual rotary pumps at a desired speed ratio.

A general schematic representation of a ground is shown in FIG. 2. Apower source, in that case a gasoline engine, drives apressure-compensated axial piston pump, which draws oil from a reservoirthrough a suction filter. A gauge measures the pressure of the output ofthe pump, and a 20 gallon per minute pressure filter passes oil toparallel connected axial piston rotary motors. Temperature compensatedflow control valves on discharge lines of the motors control motorspeeds. Tachometers indicate the speeds at which the motors drivevariable speed rotary pumps. The pumps draw grouting chemicals, fillermaterials and catalyst from containers or mixing tanks and discharge thefluids through valves and a catalyst orifice. Grouting materials aremixed in a mixing chamber in line with the injection pipe.

Hydraulic pump 4 is driven by internal combustion engine 1 or otherpower drive means. Hydraulic pump 4 draws fluid from a reservoir througha single suction line and supplies hydraulic fluid power through asingle discharge line to a number of rotary fluid motors 11, whichindividually drive an equal number of reactant pumps 16 and 17, throughrotary mechanical connecting means. There are cases in which additionalpumps are installed for additional additives to the chemical solution.The rotary hydraulic motors 11 are equipped with fluid exhaust controlvalves 12, which accurately control the speed of rotary reactant pumps16 and 17. Control valves 12 are used to obtain variable and constantratio output between the pumps 16 and 17 over the full capacity range ofeach pump.

Rotary connecting shafts of the grouting reactant pumps are equippedwith tachometers 13 to serve as indicators for the initial outputcalibration of reactant pumps 16 and 17 and to serve as means forchecking outputs of the reactant pumps during operation.

The grouting assembly is equipped with an adjustable automatic pressurelimiting switch 31 in the catalyst discharge line and power cutoff valve32 in the single hydraulic fluid pressure supply line to eliminateexceeding allowable design pumping pressures for given operations. Thegrouting assembly has pressure gauges 18 on the discharge lines of thereactant pumps 16 and 17, to indicate back pressures on the pumps and tofacilitate manual control of the injection operation. The reactantdischarge lines are equipped with indicating or recording-type flowmeters 19 for volumetric measurement of grouting materials used. Thegrouting assembly is outfitted with a magnetic flow meter and suitablecontrols for full automatic proportioning operation of thechemical-grouting solutions.

The sequence of operation of the unit in general is as follows. Primarychemical solutions together with additives and filler materials areprepared in the twin tanks 28. Catalyst for controlling gelation isprepared in tank 29. The use of the twin tanks 28 permits continuousgrouting. After one tank has been emptied, it may be refilled, whilepumping from the second tank. Each tank has an individual dischargevalve. The two tanks are connected through a Y discharge system to thesuction side of the variable volume and pressure rotary pump 17.

The discharge system of catalyst tank 29 is connected to the suction ofvariable volume and pressure pump 16.

The two pumps 16 and 17 are driven through rotary couplings by fluidmotors 11. The two fluid motors, having identical mechanicalcharacteristics, are supplied with hydraulic fluid from a singledischarge line from hydraulic pump 4, for which the power source isgasoline engine 1.

The use of fluid motors with a common power supply results in a variablevolume and pressure grouting system with infinite proportioning ratioswhich have been heretofore impossible to achieve with mechanicalvariable speed transmission proportioning drive grouting systems. Fluidmotors are equipped with flow control valves 12, which permit fluidmotor speeds to be adjusted over full working ranges of rotary speeds,ranging in this case from -2,000 r.p.m., or over full output ranges ofthe pumps. Thus, obtaining accurate individual control and proportioningof the output of pumps 16 and 17 has been accomplished.

The primary chemical solution from reactant pump 17 is dischargedthrough a rubber hose 22 or other suitable transfer lines to a commonconnection with a rubber hose from catalyst or reactant pump 16. Thiscommon connection and mixing chamber for the two solutions together arelocated downstream from cutoff valves 23 and 24. Also, the commonconnection is located downstream of the nonreturn check valve 25 in thecatalyst line. Mixing chamber 26 provides turbulence to the solutions toinsure adequate mixing. The thoroughly mixed solutions are discharged tothe point of application through injection pipes or other suitableequipment inserted into the soil or structure being treated.

Visual dial gauges l8 facilitate manual control and adjustment of pumpspeeds and output pressures during operation of the grouting system.Pressure limit switch 31 and hydraulic power cutoff valve 32 perform twofunctions. First, they permit setting a maximum allowable pressure whichcannot be exceeded and thereby reduce the hazard of excessive pressuresbeing introduced into a given structure by human failure. Second, thispressure limit switch and cutoff valve permit instantaneous start up andcutoff of the proportioning pump system by opening or closing valves 23and 2 4 by the operator at the point of application, which may beseveral hundred feet away from the proportioning pump assembly. in moredifficult and critical soil stabilization problems, it is necessary forthe operator at the point of application to have control of the overallpumping system.

Notwithstanding that specific embodiments have been used to illustratethe invention in the foregoing portion of the specification, it will beobvious to those skilled in the art that other embodiments of theinvention may be constructed without departing from the scope of theinvention. The scope of the invention is defined only in the appendedclaims.

lclaim:

1. The subterranean soil-grouting method comprising the sequential andcontinuous steps of drawing hydraulic fluid from a reservoir into asingle hydraulic pump,

increasing pressure of hydraulic fluid with the pump, and

establishing a constant hydraulic fluid flow in a single discharge linefrom the pump,

introducing full available pressure of hydraulic fluid flow to drivingmeans in each of a plurality of rotary fluid motors, individuallycontrolling exhaust fluid flow from'each rotary fluid motor, therebycausing unique exhaust pressure and flow characteristics in each of thefluid motors, and thereby rotating the motors at unique revolutionspeeds, individually rotating a plurality of shafts with the fluidmotors, individually rotating a plurality of rotary grouting reactantpumps with the plurality of shafts, each fluid motor rotating a separaterotary grouting reactant pump, by means of an individual shaft,

drawing grouting reactants from a plurality of containers,

each reactant pump being associated with an individual container,

discharging reactants from the reactant pumps through flexible dischargehoses,

passing at least one reactant through a unidirectional check valve in atleast one discharge hose,

merging the reactants and passing the reactants into a mixing chamber,

passing the mixed reactants from the mixing chamber directly into asubterranean grouting materials discharge pipe.

2. The grouting method of claim 1 further comprising the steps ofmeasuring discharge pressure in at least one of the grouting reactantdischarge hoses and shutting ofi" fluid to the fluid motors in responseto overpressure in at least one of the grouting reactant dischargehoses.

3. The grouting method of claim 1 further comprising the steps ofindividually measuring rotational speeds of the shafts, individuallymeasuring discharge pressure in the reactant discharge hoses, andcontrolling exhaust fluid flow from the motors to effect predeterminedratios between individual shaft speed measurements and to effectpredetermined ratios between individual discharge pressure measurements.

4. Portable grouting material proportioning and pumping apparatuscomprising:

a reservoir, hydraulic fluid disposed within the reservoir, a suctionline mounted in the reservoir, a rotary hydraulic pump connected to thesuction line for drawing hydraulic fluid from the reservoir, a dischargeline connected to the hydraulic pump, more than one rotary fluid motorsdirectly connected to the discharge line for receiving hydraulic fluidunder full pressure from the hydraulic pump and discharge line, exhaustlines connected to the rotary fluid motors and to the reservoir, exhaustvalves individually mounted in the exhaust lines for individuallycontrolling hydraulic fluid exhaust flow from each fluid motor, rotarymechanical connecting means connected to fluid motors for being driventhereby, more than one rotary reactant pumps connected to the connectingmeans for being rotated by the fluid motors, a plurality of reactantcontainers, reactants disposed in the containers,

intake means connected to the containers and to the reactant pumps fordrawing reactants from the containers into the reactant pumps, dischargemeans connected to the reactant pumps, mixing chamber means connected tothe discharge means for receiving and mixing reactants under pressure,and

pipe means connected to the mixing chamber means for receiving mixedreactants therefrom and for transferring the mixed reactants underpressure to subterranean spaces.

5. The grouting apparatus of claim 4 further comprising in combinationpressure-sensitive'means connected to the reactant discharge means, anda hydraulic fluid shutoff connected to the hydraulic pump discharge lineand to the pressure-sensitive means for shutting off hydraulic fluid tothe fluid motors in response to overpressure in the grouting reactantdischarge means.

6. The apparatus of claim 4 further comprising a plurality oftachometers each tachometer being attached to one connecting means forsensing operating speeds of each rotary fluid motor and reactant pump. 7

7. The apparatus of claim 4 further comprising register meansoperatively connected to the reactant discharge means .for recordingamounts of reactant pumped.

1. The subterranean soil-grouting method comprising the sequential andcontinuous steps of drawing hydraulic fluid from a reservoir into asingle hydraulic pump, increasing pressure of hydraulic fluid with thepump, and establishing a constant hydraulic fluid flow in a singledischarge line from the pump, introducing full available pressure ofhydraUlic fluid flow to driving means in each of a plurality of rotaryfluid motors, individually controlling exhaust fluid flow from eachrotary fluid motor, thereby causing unique exhaust pressure and flowcharacteristics in each of the fluid motors, and thereby rotating themotors at unique revolution speeds, individually rotating a plurality ofshafts with the fluid motors, individually rotating a plurality ofrotary grouting reactant pumps with the plurality of shafts, each fluidmotor rotating a separate rotary grouting reactant pump, by means of anindividual shaft, drawing grouting reactants from a plurality ofcontainers, each reactant pump being associated with an individualcontainer, discharging reactants from the reactant pumps throughflexible discharge hoses, passing at least one reactant through aunidirectional check valve in at least one discharge hose, merging thereactants and passing the reactants into a mixing chamber, passing themixed reactants from the mixing chamber directly into a subterraneangrouting materials discharge pipe.
 2. The grouting method of claim 1further comprising the steps of measuring discharge pressure in at leastone of the grouting reactant discharge hoses and shutting off fluid tothe fluid motors in response to overpressure in at least one of thegrouting reactant discharge hoses.
 3. The grouting method of claim 1further comprising the steps of individually measuring rotational speedsof the shafts, individually measuring discharge pressure in the reactantdischarge hoses, and controlling exhaust fluid flow from the motors toeffect predetermined ratios between individual shaft speed measurementsand to effect predetermined ratios between individual discharge pressuremeasurements.
 4. Portable grouting material proportioning and pumpingapparatus comprising: a reservoir, hydraulic fluid disposed within thereservoir, a suction line mounted in the reservoir, a rotary hydraulicpump connected to the suction line for drawing hydraulic fluid from thereservoir, a discharge line connected to the hydraulic pump, more thanone rotary fluid motors directly connected to the discharge line forreceiving hydraulic fluid under full pressure from the hydraulic pumpand discharge line, exhaust lines connected to the rotary fluid motorsand to the reservoir, exhaust valves individually mounted in the exhaustlines for individually controlling hydraulic fluid exhaust flow fromeach fluid motor, rotary mechanical connecting means connected to fluidmotors for being driven thereby, more than one rotary reactant pumpsconnected to the connecting means for being rotated by the fluid motors,a plurality of reactant containers, reactants disposed in thecontainers, intake means connected to the containers and to the reactantpumps for drawing reactants from the containers into the reactant pumps,discharge means connected to the reactant pumps, mixing chamber meansconnected to the discharge means for receiving and mixing reactantsunder pressure, and pipe means connected to the mixing chamber means forreceiving mixed reactants therefrom and for transferring the mixedreactants under pressure to subterranean spaces.
 5. The groutingapparatus of claim 4 further comprising in combinationpressure-sensitive means connected to the reactant discharge means, anda hydraulic fluid shutoff connected to the hydraulic pump discharge lineand to the pressure-sensitive means for shutting off hydraulic fluid tothe fluid motors in response to overpressure in the grouting reactantdischarge means.
 6. The apparatus of claim 4 further comprising aplurality of tachometers each tachometer being attached to oneconnecting means for sensing operating speeds of each rotary fluid motorand reactant pump.
 7. The apparatus of claim 4 further comprisingregister means operatively connected to the reactant discharge meAns forrecording amounts of reactant pumped.